<?php
/**
 * Slipstream :: Highly adaptive dependency injection framework
 * Copyright 2010-2011 Ian Unruh (Xerof3ar)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
namespace Slipstream\Configuration\Lifetime;

use ArrayObject;
use Slipstream\Configuration\AbstractPolicy;
use Slipstream\Configuration\PolicyInterface;

/**
 *
 *
 * @author Ian Unruh (Xerof3ar) <ianunruh@gmail.com>
 * @since Class avaliable since release 1.0
 */
abstract class AbstractLifetimePolicy extends AbstractPolicy
{
	/**
	 * Returns true if this policy matches another policy
	 *
	 * @param PolicyInterface $policy
	 * @return bool
	 */
	public function matches(PolicyInterface $otherPolicy)
	{
		return ($otherPolicy instanceof self);
	}
	
	/**
	 * Merges a set of policies with this policy to create a single policy
	 *
	 * @param ArrayObject<PolicyInterface> $policies
	 * @return PolicyInterface
	 */
	public function merge(ArrayObject $policies)
	{
		$lastOffset = (count($policies) - 1);
		return $policies->offsetGet($lastOffset);
	}
}